1. Field of the Invention
The present invention is directed to flexible, compressed intravaginal rings comprising a substantially homogeneous compressed mixture comprising a polymethacrylate, a plasticizer, a thickener, and an active agent, and a method of using the same. The present invention is also directed to a method of making and an apparatus for making flexible, compressed intravaginal rings utilizing a compression tooling apparatus.
2. Background Art
Intravaginal drug delivery is an increasingly utilized method of drug administration. Intravaginal dosage forms can provide good adsorption of active agents as well as a means to avoid the first-pass effect in the liver. As a result, intravaginal delivery is an efficacious method for administering many types of active agents. Intravaginally administered active agents can be targeted for direct diffusion through the vaginal tissues to provide a local effect, or can be absorbed through the mucosa the vaginal tract, for example, to provide a systemic effect. Further, there are numerous conditions within and outside the vaginal and/or urogenital tract, such as hormonal dysfunctions, inflammation, infection, pain, and incontinence, that can be treated by intravaginal administration of pharmaceutically active agents.
Of the several methods of intravaginal drug delivery in the art, such as for example, the use of intravaginal rings, intrauterine devices, and intravaginal pessaries (see e.g., U.S. Pat. Nos. 4,823,814; 4,607,630; 4,553,972; 4,286,587; and 4,249,531), intravaginal rings provide a versatile, comfortable method to deliver active agents via the intravaginal route.
However, there is a need in the art for improved intravaginal rings capable of maintaining active agents in the vaginal and/or urogenital tract for extended periods of time to allow for maximum and uniform absorption of the active agent at the desired location within the vaginal and/or urogenital tract.
There is also a need in the art for a method and apparatus for making the flexible, compressed intravaginal rings of the present invention. It is generally known to make ring-shaped objects through molding or compression. Compression tooling apparatus exist for making ring-shaped tablets on a small scale size (see e.g., U.S. Pat. No. 5,672,313), but there exists a need for a compression tooling apparatus that can make a flexible, compressed ring-shaped object that is the size of an intravaginal ring.